With the new P100D battery pack, Tesla is introducing its first third-generation battery pack technology in production vehicles. A successful deployment of the technology would be a good sign for Tesla’s third-generation platform and therefore, crucial for the Model 3.

To be clear, we are talking about battery pack level improvements here. You have the battery cells, which CEO Elon Musk confirmed were the same in the new P100D battery pack, and the cells go in battery modules. You put several of these modules together to form a battery pack.

During a conference call with the media earlier this week, Musk tried to explain different challenges between battery cell, module and pack engineering:

“People often think that a battery and a battery pack is the same thing, but the technical complexity once you get to do a large number of cells in a pack is very much on the module/pack level. You can think of the cell level as being a chemical engineering problem and the module/pack level as being a mechanical, electrical and software engineering problem.”

The improvements were made at the battery module/pack level. Musk briefly talked about the changes during the call:

“The cell is the same, but the module and pack architecture is changed significantly in order to achieve adequate cooling of the cells in a more energy dense pack and to make sure we don’t have cell to cell combustion propagation.”

The pack is definitely more energy dense. From the 90 kWh pack, the energy increased by 11%, but the weight of the pack only by 4%, which means that Tesla achieved a significant battery energy density increase at the pack level since the introduction of the 90 kWh pack just over a year ago (July 2015).

The improvement was achieved through the development of Tesla’s third-generation platform on which the Model 3 will be the first vehicle to launch. Tesla CTO JB Straubel confirmed last year that the automaker was developing the new platform and battery architecture for the Model 3.

Straubel also commented on the new pack:

“It is a pretty big change on the battery module and pack technology. It’s a complete redo of the cooling system, which is quite unique to Tesla and that we have been improving on for many years. This new pack is the next version of that. “

Straubel also specified that the goal with the P100D was for the pack’s external to stay the same in order for retrofits to be available for current owners. It means that the energy density improvement is really at the module level.

Musk added that with the current cell form, he doesn’t expect to be able to improve the energy density of the battery pack. He described the new 100 kWh pack’s energy density as 11 pounds in a 10-pound bag. The Model 3 battery pack will make use of the battery module and battery pack cooling improvements, but it will also feature the new cell, meaning that we can expect a higher energy density even though the energy capacity should be lower since it’s a smaller and less expensive vehicle than the Model S and X.

Straubel confirmed that some of the improvements in the new P100D battery pack will make it to the Model 3:

“Some of the key improvements that enabled the new pack are directly on the roadmap for the technologies that make Model 3 possible.”

Musk then made a direct link with the Model 3 and the new P100D version of the Model S and X:

“Yes, it is an expensive car, but that is what is paying for the Model 3 – both in terms of free cash flow and learning more about its core technology.”

He concluded by saying that anyone who cares about the Model 3 should appreciate anyone buying the new P100D. Based on his planned production, he expects that over 200 people will order the new $135,000+ version every week for the next few months.